The Chamavi were a Germanic people of Roman imperial times who lived north of the Roman border (Limes) in the Rhine river delta region, in what is now the Netherlands, and perhaps stretching into what is now Germany.

In the Roman records of the third and fourth century, when the tribes of this region began to be categorized as Franks or Saxons, the Chamavi were at different times listed as both, and sometimes distinguished from both. In the third century Chamavi and Frisians, apparently both considered Frankish peoples, settled in the Rhine delta during a period when the empire lost control of the region. After being defeated and ejected, they were once again mentioned as entering the area in the 4th century, but this time described as a Saxon people. After being once again defeated, they were forced to supply soldiers to the Roman military.

Their name probably survives in the region called Hamaland, which is in the Gelderland province of the Netherlands, near present day Deventer between the IJssel and Ems rivers. In France, one area where the Romans settled them also continued to be named after them into the Middle Ages.

The etymology of the Chamavi name is uncertain, but it is generally believed to come from a Germanic language. Its construction is similar to those of neighbouring peoples, the Batavi and Frisiavi (Frisiavones).

The Reallexikon der Germanischen Altertumskunde lists three speculative proposals which have been made for a Germanic etymology:

A Germanic name has been reconstructed as *Hamawiz from the name of the Matrones Hamavehae [de], evidence for whom was found between Jülich and Aachen.

One of the first possible records of the Chamavi is an uncertain one. According to a surviving copy of Velleius Paterculus, in 4 AD Tiberius crossed the Rhine and attacked, “cam ui faciat Tuari Bructeri”. This is often corrected in modern texts to the sequence, "Cananefates, Chattuari, Bructeri". However, it has been argued that the Cananefates (in present day South Holland) were unlikely to be in conflict with the Romans at this point, and that the original text may have referred to the Chamavi instead, implying that they lived near the Rhine, and west of the other two tribes at this time.

Tacitus reports in his Annals that in the time of Nero (apparently 58 AD), the Ampsivarii, having been ejected from their homes further to the north near the river Ems, pleaded with Roman authorities to allow them to live in a military buffer zone on the northern bank of the Rhine, saying that "these fields belonged to the Chamavi; then to the Tubantes; after them to the Usipii". These fields, were on the northern bank of the Rhine between the IJssel and Lippe, to the southeast of modern Hamaland, south of modern Twente where the Tubantes lived, and to the northwest of the Bructeri. This is known because during an earlier campaign against the Germanic tribes in 12 BC, the settlement area of the Usipii which is believed to be the same one mentioned by the Ampsivarii, bordered the Lippe to the south, which is where the country of the Sicambri began at that time. The record indicates that before 12 BC the Chamavi's lands extended to the Rhine, but that they subsequently moved out of that area.